The thermal regeneration of charged carbon-containing adsorbents, especially active carbons, generally has been carried out in multilevel or rotary kiln furnaces in which the adsorbent is continuously passed through the regenerating furnace and is there subjected to heat and material exchange with the ambient conditions to effect release of the contaminants or adsorbed components from the adsorbent.
Since heat and material exchange is vital to the regeneration process, it has been proposed to promote both by the use of a fluidized bed furnace in which the fluidized bed is constituted by fluidizing the particles of the adsorbent without an additional bed material.
Fluidized bed regeneration of carbon-containing adsorbents has been applied especially effectively heretofore in the large scale regeneration of active carbons used in the treatment of waste water.
A process for regenerating and recovering reusable pulvurulent active carbon by a decomposition and gasification or distinctive distillation of sludge obtained from waste water or sewage treatment utilizing active carbon for adsorption of impurities in the waste water has been proposed heretofore, in which the pulvurulent adsorbent-containing material and the sludge powder are treated in a regeneration furnace with combustion flue gases, in German patent document (Open Application - DE-OS 26 14 021) in which the organic components adsorbed on the active carbon can be selectively thermally decomposed and gasified. The active carbon is massively entrained in the turbulent flow and a regenerated active carbon is recovered.
This process utilizes a separation of the regenerated active carbon but has not been found to be capable of restoring the adsorption activity of the product to a point which is sufficiently close to that of fresh active carbon to enable it to be used for the treatment of commercial industrial waste waters.